Update privilege requirement to manage Logstash xpack

update document for system indices API #12291

docs/static/settings/configuration-management-settings.asciidoc

@@ -53,8 +53,10 @@ section in your Logstash configuration, or a different one. Defaults to
 If your {es} cluster is protected with basic authentication, these settings
 provide the username and password that the Logstash instance uses to
 authenticate for accessing the configuration data. The username you specify here
-should have the built-in `logstash_admin` role and the customized `logstash_writer` role, which provides access to `.logstash-*`
+should have the built-in `logstash_admin` role and the customized `logstash_writer` role, which provides access to system
 indices for managing configurations. 
+Starting from Elasticsearch version 7.10, `logstash_admin` inherit a cluster privilege `manage_logstash_pipelines` to manage centralized pipeline management. 
+If a user has derived their own roles and manually granted access to the .logstash index, those roles will continue to work in 7.x but will need to be updated for 8
 
 `xpack.management.elasticsearch.proxy`::
 
@@ -98,7 +100,7 @@ This setting is an alternative to both `xpack.management.elasticsearch.username`
 and `xpack.management.elasticsearch.password`. If `cloud_auth` is configured,
 those settings should not be used.
 The credentials you specify here should be for a user with the `logstash_admin` role, which
-provides access to `.logstash-*` indices for managing configurations.
+provides access to system indices for managing configurations.
 
 `xpack.management.elasticsearch.api_key`::